Six hours, not never: the ICU filter notice the MHRA issued today
What happened
The UK's medicines and devices regulator has issued a new safety notice to hospitals, and it is about timing. On 13 October 2026 the Medicines and Healthcare products Regulatory Agency (MHRA) published a Device Safety Information notice, reference DSI/2026/014. It tells hospital teams to wait, where they safely can, before giving a particular antifungal medicine to patients on a kidney support machine. The machine is used for continuous renal replacement therapy, or CRRT: a slow form of dialysis that runs over about 24 hours, mostly in intensive care, for people who are critically ill and whose blood pressure is unstable. Blood passes through a filter with a very fine membrane, doing the work the kidneys cannot do for the moment. The medicine is caspofungin, one of a group of antifungals called echinocandins. It is given into a vein for serious fungal infections in adults and children, and when doctors strongly suspect one in someone whose immune system is very weak. The two can interact in a way nobody intended. Some CRRT filters use membranes made from a plastic called polyacrylonitrile, or PAN, and published evidence has shown caspofungin can stick to them. The medical word is adsorption. If the drug sticks to the filter, less of it reaches the patient and the treatment may not work. In a critically ill person with a fungal infection in the blood, the MHRA says that can be potentially life-threatening. The risk looks highest right at the start, when a brand new membrane or filter circuit has been set up, because the sticking falls away as the membrane becomes saturated. So the advice is about the clock. Where possible, echinocandins such as caspofungin should be given at least six hours after CRRT has been started, and at least six hours after a routine change of the filter circuit. But CRRT itself should carry on as the patient needs it, and should not be delayed or paused just to fit a medicine in, unless the responsible doctor decides that is right for that person.
Why this matters
Most safety alerts ask someone to stop using a product, or to send a batch back. This one asks for a change to the order in which things are done. That matters because the people affected are among the sickest in the hospital. Someone on CRRT in intensive care has failing kidneys. If they also have a fungal infection in the blood, they need the antifungal to work the first time. It also matters because the problem is invisible. A medicine that sticks to a filter does not look like a mistake. The pump runs, the infusion goes through, the chart gets signed, and the drug level in the blood is lower than anyone expects. The MHRA makes this point directly: if a patient on CRRT is not responding to treatment, the team should consider the filter itself as a possible reason, not only the infection. The regulator is clear this is not only about one drug or one filter. The same risk cannot be ruled out for other membrane types used in CRRT, or for other medicines with similar properties, and comparative studies between membranes have not been done. The six-hour advice is a precaution built on incomplete knowledge, not a final answer. The MHRA worked on the notice with the UK Kidney Association, the NHS England National Patient Safety team and the devolved administrations, and a letter to clinicians has gone out alongside it. There is one more reason it matters: the UK has deliberately taken a different route from the rest of Europe.
What the evidence actually says
This story did not start this week. It started in Europe, and the UK has read the same evidence and reached a different practical conclusion. The European Medicines Agency's safety committee, PRAC, concluded that PAN-based membranes in CRRT can bind caspofungin and reduce how well it works. A letter went to healthcare professionals across Europe on 9 October 2025, and its advice was blunt: in patients treated with caspofungin during CRRT, PAN-based membranes should be avoided, and teams should use a different membrane or a different antifungal. What was that built on? According to the letter: a case in the medical literature in which a bloodstream candida infection reversed when CRRT with a PAN filter was started and stopped; four fatal cases in which caspofungin appeared not to work on CRRT with the same membrane type; and two laboratory studies suggesting PAN membranes took the drug up, with the effect continuing even at a higher dose. The MHRA looked at all of that, plus studies published since, and talked to UK clinicians. It decided the European approach would not work here, and said why. Swapping filters is limited by which CRRT machines UK hospitals actually have. Avoiding echinocandins altogether would be likely to have a serious clinical impact, because they are a first-line treatment for invasive candidiasis and intensive care patients are more likely to get fungal infections. Switching antifungals is not a free choice either, because of sensitivities and drug resistance in candida. So the MHRA chose timing instead of avoidance. The studies it cites indicate the sticking is not specific to one drug, is highest immediately after a new membrane or circuit starts, and falls as the membrane fills up. Giving the dose after that early window should reduce how much drug is lost. It is worth being honest about the uncertainty. The notice references a letter and a reply published in the journal Infectious Diseases and Therapy in 2026, in which researchers disagree about how strong the evidence really is. This is a suspected risk being managed carefully, not a closed case, and the MHRA's wording reflects that.
Qurexa perspective
We want to be straightforward: this changes nothing about the medicines we deliver, and nothing you need to do at home. Caspofungin is given through a drip in hospital, usually in intensive care, and CRRT does not happen outside hospital. We are covering it because it makes a point we come back to often. When you take a medicine can matter as much as whether you take it. In intensive care that means waiting six hours after a filter change. At home it is simpler, but the principle holds: a tablet taken at the wrong time of day, or doubled up after a missed dose, can work less well than intended. That is why our adherence support exists. If you are ever unsure when to take something, ask a pharmacist.
Practical advice
If you are a patient or a relative, there is no action for you to take. The notice is addressed to the hospital teams who run CRRT and who prescribe, dispense and give caspofungin. The MHRA's own advice to pass on to patients is that anyone with concerns should speak to their healthcare professional. If someone you love is in intensive care on kidney support and being treated for a fungal infection, you are allowed to ask whether the team has seen the new notice. A good team will not mind being asked. If you work in a clinical team, the notice asks you to: Give echinocandins such as caspofungin at least six hours after CRRT starts, and at least six hours after routine filter circuit set changes, where that is clinically possible. Not delay or pause CRRT purely to fit a dose in, unless the responsible clinician judges it necessary. For a patient already on an echinocandin before needing CRRT, consider delaying the next dose or the start of CRRT only if clinically viable, and watch for lack of effect where the start of CRRT overlaps with the half-life of the drug already given. Make sure everyone involved knows, including those setting up the circuit and those prescribing, dispensing and administering the drug. Treat filter binding as a possible explanation when a patient is responding less than expected to any drug given during CRRT. Review local protocols and standard operating procedures to cover drug adsorption during CRRT and dose timing. Ask for help early: specialist pharmacist, infectious disease, medical microbiology and mycology advice is available nationally, including on fungal antigen testing. Report problems: in England, Wales and Northern Ireland through the Yellow Card website or app; in Scotland through the Incident Reporting and Investigation Centre and your local incident recording system.
What to know
In short: on 13 October 2026 the MHRA told UK hospitals that caspofungin, and similar antifungals, can stick to the PAN-based filter membranes used in continuous kidney support, which may leave the treatment less effective in patients who badly need it to work. The fix it recommends is timing: give the antifungal at least six hours after the machine starts or the filter circuit is changed, and never hold up the kidney treatment itself to do it. Europe's regulator took a stricter line a year ago and said to avoid those membranes altogether. The MHRA decided that was not workable here and chose a schedule change instead. Both agree on the underlying worry. There is nothing for patients at home to change, and nothing that affects pharmacy deliveries. If a relative is in intensive care, it is reasonable to ask whether the team has seen the notice. Sources: Medicines and Healthcare products Regulatory Agency, 'Continuous renal replacement therapy (CRRT): Consider delayed administration of concurrent echinocandins, such as caspofungin, to reduce the risk of adsorption onto new polyacrylonitrile (PAN)-based filter membranes (DSI/2026/014)', 13 October 2026, https://www.gov.uk/drug-device-alerts/continuous-renal-replacement-therapy-crrt-consider-delayed-administration-of-concurrent-echinocandins-such-as-caspofungin-to-reduce-the-risk-of-adsorption-onto-new-polyacrylonitrile-pan-based-filter-membranes-dsi-slash-2026-slash- ; European Medicines Agency, 'Direct Healthcare Professional Communication (DHPC): Caspofungin - Avoid use of polyacrylonitrile membranes during continuous renal replacement therapy', 9 October 2025, https://www.ema.europa.eu/en/documents/dhpc/direct-healthcare-professional-communication-dhpc-caspofungin-avoid-use-polyacrylonitrile-membranes-during-continuous-renal-replacement-therapy_en.pdf ; Agencia Espanola de Medicamentos y Productos Sanitarios, 'DHPC Caspofungina', 9 October 2025, https://docswebaemps.aemps.es/PDF/DHPC_Caspofungina_09_10_2025.pdf This article is for general information and does not replace advice from a doctor, pharmacist or other qualified healthcare professional. If you have questions about a medicine you or a relative has been prescribed, speak to your pharmacist or your hospital team.
Related articles
Eight pages to a minister: what the data guardian says trust is worth
On 12 October 2026, the government published a letter about who should be trusted with NHS patient data. It was written by Dr Nicola Byrne, the National Data G…
Update: the tests came back, and it was not plague
This is a follow-up to a story we covered on 5 October, when nearly 200 people were being monitored after the death of a laboratory worker in Siberia. There has…
Twenty-four hours to spot an outbreak: the target set in Berlin on Monday
On Monday 12 October 2026, the World Health Organization launched a new five-year plan for the way it watches for outbreaks. The launch took place in Berlin, at…